code: def test_overwrite_df():
      data_path = os.path.join(this_dir, "data", "1b5e_1.mol2")
      pdmol = PandasMol2().read_mol2(data_path)
  
      def overwrite():
          pdmol.df = pdmol.df[(pdmol.df["atom_type"] != "H")]
  
      expect = (
          "Please use `PandasMol2._df = ... `"
          " instead\nof `PandasMol2.df = ... `"
          " if you are sure that\nyou want"
          " to overwrite the `df` attribute."
      )
  
      assert_raises(AttributeError, expect, overwrite)
  
file_path: biopandas/biopandas/mol2/tests/test_pandas_mol2.py
imports: import os
  from biopandas.mol2 import PandasMol2
  from biopandas.mol2.mol2_io import split_multimol2
  from biopandas.testutils import assert_raises
label_desc: Use image node_id 6 for calling a global function with example usage: test_overwrite_df() without return types